cho tam giac ABC co AB=AC. Ke duong cao AH vuong goc voi BC
a/CM Tam giac AHB =tam giac AHC
b/ Lay diem G Tren doan thang AH sao cho AG=2GH. Goi M la giao diem cua BG va AC. CM:
M la trung diem cua AC
c/ Goi N la trung diem cua AB. CM : ba diem C G N thang hang
HELP ME mk sap co bai kiem tra roi
cho tam giac abc deu goi g la trung tam cua no tren tia ag lay d sao cho g la trung diem cuja ad chung minh tam giac bgc deu
cho tam giac abc deu goi g la trung tam cua no tren tia ag lay d sao cho g la trung diem cuja ad chung minh tam giac bgc deu
cho tam giac ABC vuong tai A, co AB=4, AC=5
a) Hay so sanh so do goc B va goc C cua tam giac ABC
b)tia phan giac cua goc ABC cat canh AC tai D. Ke DM vuong goc voi BC tai M chung minh tam giac ABM=tam giac MBD
c)Hai tia MD va BÂct nhau tai E . tia BD cat EC tai N . Chung minh goc BNC=90o
d) Goi K la trung diem cua DE . Chung Minh CK=3/4 EC
cho tam giac ABC co AB = 3, AC = 4. diem I nam trong tam giac va cach deu 3 canh cua tam giac ABC. goi M la chan duong vuong goc ke tu diem I xuong BC. Tinh BM
Cho tam giac ABC . Tren tia doi tia AB lay diem C sao cho AE=2AB. Tren tia doi tia BC lay D sao cho BC=BD .CM
a) A la trong tam cua tam giac CDE
b)CA di qua trung diem cua DE
cho tam giác abc can tai a ke ah vuong goc voi bc chung minh hb=hc va ah la phan goc a lay d tren tia doi bc sao cho bd=ba cm de song song voi ah so sanh goc dab va goc bah lay f sao cho d la trung diem ef goi g la trung diem ec chung minh f b g thang hang
tam giac abc co am la trung tuyen, g la trong tam thi ag/am bang may
Cho tam giac MNP .MQ là đường trung tuyên .Trên tia đôi cua tia QM lây điểm O ao cho QO=QM chung minh rằng
a)Tam giac QMN=Tam giac QOP
b)MN ong ong PO
